This study aimed to explore the influence of migration on the oral health outcomes among the early childhood children in Yulin, and provide a basis for promoting rural left-behind children′s oral health in Yulin.

In September 2021, three townships were randomly selected in the townships of Yuzhou District, Yulin City. The rural kindergartens were numbered in the selected townships, then four rural kindergartens were randomly selected in each township, and a total of 12 kindergartens with 1 300 rural children at the age of 3-5 years were recruited for oral examination. Their deciduous teeth were examined by dentists and oral health questionnaire survey was conducted for their parents. The differences between the left-behind and non-left-behind children were analyzed in demographic, socioeconomics and oral health related indicators. Multivariate logistic regression was used to analyze the influence of parental migration factors on oral health related indicators.

The caries prevalence of the left-behind children (79.0%) was higher than that of the non-left-behind children (62.9%) with statistical significance ( χ² = 31.639, P<0.001) . The mean dmft of the left-behind children (5.2 ± 4.6) was significantly higher than that of the non-left-behind children (3.6 ± 4.3, χ² = 5.715, P<0.001) . The proportion of the left-behind children taking sweetmeats more than once a day (75.5%) was statistically higher than that of the non-left-behind children (68.8%, χ² = 6.163, P = 0.013) . The proportion of the left-behind children sleeping with sugary liquid bottles (38.0%) was significantly higher than that of the non-left-behind children (31.3%, χ² = 5.496, P = 0.019) . The proportion of the left-behind children using fluoride toothpaste (14.9%) was significantly lower than that of the non-left-behind children (19.9%, χ² = 4.474, P = 0.034) . The oral health attitude scores of the parents in the left-behind children group (5.5 ± 1.8) were statistically lower than those of the parents in the non-left-behind children group (5.8 ± 1.6, t = -4.647, P = 0.008) . The proportion of the visible plaque index over 20% in the left-behind children group (59.8%) was significantly higher than that of the non-left-behind children group (45.1%, χ² = 23.137, P<0.001) . The proportion of the left-behind children taking sweetmeats more than once a day was higher than that of the non-left-behind children (OR = 1.368, 95% CI = 1.040-1.801) . The oral health attitude scores of the parents in the left-behind children group were lower than those of the non-left-behind children group (t = -2.168, P = 0.030, 95% CI = -0.406--0.020) . The proportion of the visible plaque index in the left-behind children group was higher than that of the non-left-behind children group (OR = 1.658, 95% CI = 1.278-2.152) . The risk of caries in the left-behind children was 1.958 times higher than that of the non-left-behind children (OR = 1.958, 95% CI = 1.378-2.781) .

The oral health behavior and oral hygiene of the rural left-behind children in Yuzhou District, Yulin, were worse than those of the non-left-behind children, and the caries prevalence of deciduous teeth in the former was higher than that of the latter. Parental migration might be a significant factor on the high frequency of sweets intake, low parental oral health attitude, low oral hygiene and high caries prevalence of the rural early childhood children in Yuzhou District.